if you're writing something like a wrapper service around a database, there should be no state at all. (i'd argue it's high time that databases moved forward with respect to security and hardening such that they can be accessed nearly directly or... directly)

if you're building a thing where state is required, then yes, it should be minimized. but i'd argue against dogmatic use of immutable data records and really think about what that sort of design is attempting to achieve: reduction of sprawl in places in the code where a piece of data is updated.

the goal is to put all that stuff in one easy to find place. that can be manifested or violated (sometimes with great acrobatics) regardless of whatever rules are followed. (even oop!)